This invention relates generally to interlocked continuous webs, and more particularly to the provision of sets of inter-engaging tongues staggered along at least a marginal edge of the webs for interlocking them together and for facilitating an easier separation of the plies.
For the purpose of releasably interlocking continuous super-imposed webs together, interengaging superimposed tongues have been provided in such webs for preventing both longitudinal and transverse relative shifting of the webs while at the same time permitting the webs to be separated or peeled apart during decollating. Such tongues may be spaced along one or both marginal edges of the webs and are provided by punching or slitting through the webs to form substantially U-cuts forming tongues integrally attached to the webs and having free ends and side edges provided by the deviating slits. The tongues may likewise be formed by substantially H-shaped cuts.
At each spaced location along the marginal edge or edges, one or more of such superimposed tongues may be provided depending on the holding strength required for the number of webs to be interlocked together. However, where more than one of such superimposed tongues are present at each spaced location, they typically lie along a line perpendicular to their adjacent marginal edge. Consequently, when such webs are peeled apart during a web decollating operation, the interengaging tongues between webs at each location along the marginal edges unlock or disengage simultaneously as the webs of the assembly are decollated. Hence, the decollating operation is not smooth by reason of a "tug" or a "snag" experienced each time a set of the laterally disposed sets of tongues are peeled apart. In other words, the resistance offered by the two or more interengaging tongues at the spaced locations along the marginal edges is sufficiently great as to affect the smooth decollating operation of the webs.